You should have approached the airline for an "escort pass". When the elderly, unaccompanied children, handicapped, etc. travel these passes are issued to the "greeters" if warranted. Your wife could have met grandma and escorted her through customs.
That would have stifled conversation on the Internet as to how terrible it is having to suffer with visiting relative citizens who tote a disdain for our country.
I think you just made my day, and my family's as well. This is exactly the kind of information I was hoping somehow to find. A big thank you to you and yours.